Benjamin F. Welker was born on April 25, 1836, in Indiana to Daniel and Nancy Welker. His father was a potter who owned $500 of real estate by 1850. He grew up and attended school in Georgetown, Indiana, and by 1860, he was working as a schoolteacher.
He enlisted in the Union army on July 27, 1861, and he mustered in as a corporal in Company C of the 23rd Indiana Infantry. The regiment took part in the Battle of Shiloh, the siege of Vicksburg, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He mustered out on July 23, 1865.
He returned to Indiana after the war, and he married Mary A. Bruder on January 29, 1867. They had no children. They lived in New Albany, Indiana, and Welker worked as a clerk. By 1870, he owned $200 of personal property. By 1880, he was working as a horse trader. He began working as a pension agent in the late 1800s. He died of heart disease in New Albany on January 11, 1911.